Opponents of net neutrality being enforced often say that ISPs would likely not end up censoring or stopping the flow of any data, as people could simply switch to another ISP. However, as recent as last August, there was a bout with this very situation. AT&T blocked Apple's FaceTime from being used on their network. Now, this may not seem like a huge issue, but let's take a closer look at what was going on there:

AT&T was blocking the use of a product made by an entirely different company from being used by a consumer that purchased the product. AT&T generously said that they would allow people to use the product (software made by a different company on hardware made by that same different company) for no extra charge, under the condition that the consumer subscribes to a certain plan. This is like the milk man telling me that I can use my printer for free as long as I subscribe to a year of milk on his three gallon a week plan.

I personally see huge problems with AT&T doing this. It's "Company A" being able to block the use of a product from "Company B" simply because the data will be traveling through company A's lines. Let's take an even closer look while we're here. The product being blocked is, as mentioned earlier, Apple's FaceTime. For those not in the know, this can easily be seen as a competitive product to AT&T's phone services. If you have an iPhone and an unlimited data plan, you might no longer even need to purchase phone service from AT&T anymore. So there, we've hit the core of it. Given the chance, companies will most definitely censor competitors' products.